1. Field of the Invention
The present invention is related to fiber optic switching. In particular, the present application is related a micromachine actuated fiber optic switch and a process for making and using same.
2. Description of Related Art
With the rapid growth of the fiber optic based communications and computing, there is now and will continue to be a persistent need for capabilities to switch fiber optic signals. In addition, because of ever decreasing form factors, there is a corresponding need to provide fiber optic switching capabilities in ever smaller package sizes.
Conventional systems for switching or directing fiber optic signals tend to be undesirable in that large mirrors and supporting apparatus are required which give rise to undue expense, unreliability, and inconsistency in optics. Moreover, problems with process control particularly for micromachine parts give rise to inconsistent yield and inconsistency in performance between parts manufactured according to switch design.
Fiber optic switch design and optics design are integrally related because fabrication methods are deeply influenced by the size, shape, and structure of the optics, which factors ultimately determine what methods are feasible. One goal is to minimize assembly costs. However, since fibers used in fiber optic communication are typically manufactured separately from the switch, they must be assembled into a final product. Other parts may also need to be manually placed into a manufactured switch design if necessary and sufficiently simple. Although high volume manufacture may involve robotic assembly, delicate placement and alignment of optical fibers in switch assemblies still poses practical difficulties and costs.
Accordingly, it is would be appreciated in the art for a method and apparatus for switching fiber optic signals and a process for making and using same which overcomes these and other difficulties. Such a method and apparatus would provide for placement and alignment of optical components, such as optical fibers and the like within switch assemblies.
Therefore in accordance with various exemplary embodiments of the present invention, a method and apparatus for switching optical signals are described. The optical switch of the present invention may include a first optical input/output port, plurality of second optical input/output ports, and an optical guiding assembly coupled therebetween. The optical guiding assembly is preferably configured to moveably direct an optical signal between the first optical input/output port and a selected one of the plurality of second optical input/output ports.
Alternatively, the optical guiding assembly further preferably includes a optical micro-element assembly, and an actuator assembly, which actuator assembly may be mechanically coupled to the optical micro-element assembly and may be configured to moveably direct the optical micro-element assembly to a predetermined position. It should be noted that the predetermined position corresponds to a placement of the actuator sufficient to cause the optical micro-element assembly to direct the optical signal to the selected one of the optical input/output ports.
As will be described in greater detail hereinafter, the optical microelement assembly in accordance with various exemplary embodiments may include various structures capable of directing and or deflecting light signals such as for example, a micro-lens, an etched lens, a ball lens, a mirror, and the like and the actuator assembly may include, for example, a comb drive, which comb drive may be integrated into the substrate through the use of, for example, micro-machining, semiconductor-style device manufacturing techniques, or the like.
Thus in accordance with various exemplary embodiments an actuating assembly may be integrated into the substrate and an optical micro-element integrated into the actuating element. The process used for integration may include Deep Reactive Ion Etching (DRIE). It should be noted that the optical micro-element has an optical axis parallel to a horizontal plane associated with the substrate and accordingly the actuating assembly is configured to move the optical micro-element within the horizontal plane. The switch assembly may preferably include a first input/output port and a plurality of second input/output ports. The optical signal is directed to a selected one of the plurality of second input/output ports from the first input/output port by moving the optical micro-element within the horizontal plane in a direction perpendicular to the optical axis using the actuating assembly. In order to control the movement and precision of the actuating assembly a feedback controller and a plurality of sensors may be used. Accordingly, one of the plurality of sensors corresponding to the selected input/output port generates a feedback signal associated with, for example, a level of alignment of the optical signal. It will be appreciated that signal intensity maxima, for example, may be used as an indication of alignment. The feedback signal may then be used to correct the position of the actuator assembly so as to correct the level of alignment.